ejm

closed chamber hads 2.25 int 1.88 ex stock oval bbc heads what dome can a guy run had flat tops in it and valves were taping pistons just needing a piston that will work

hotrod1994

ok they were hitting with flat tops right?
if so look for a dish piston not a dome
or find one with a smaller compression height
im not sure on a bbc but a sbc stock is 1.560 and a lot of oem replacements are 1.540
meaning the piston will not rise as high in the cylinder
try looking at silvolite there an oem replacement made by keith black not sure if they will have for your application but worth a shot

hope this helped
-logan

ejm

but with a dome piston aren't the valve releifs bigger?

zipper06

You can use a .250 dome piston with a closed chamber head and up to a .600 lift cam, i was doing that in the mid 80's with both a 427 and a 454 engine with a stock steel shim gaskets, if the heads haven't been milled too much and that could be the problem, maybe some one milled the heads a bunch. Either way it's best to check the valve to piston clearance before final assy. you need min. .080 on the intake and .120 on the exhaust clearance. I use modeling clay for checking.

Most of the dealers sell these pistons, jegs, summit, just be sure you tell them they are for closed chamber heads.

JMO

Zip.

ejm

so if the heads are milled to much does a guy hafta go with a thicker gasket? if so hopefully they make one thick enough?

DogGear

Hey, If valves are hitting pistons and you cant rotate by hand any further.
Remove the valve springs from no1 cyl put head back on rotate it and see what kinda valve depth allowance your getting and keep your head gasket in the 30thousandths or .030 when figuring and measure and remeasure, cam should be straight up for this test to start but its just one of many starting points. If you have any questions you can Pm if you would like.